Method of and apparatus for cracking oil



KBTHQD OF AND APPARATUS FOR CRACKING OIL K w 9 W 9 B E5 2 a 67 w d l x li w F, A v M ii 4 z m T 0 mm m a A z V m WV p Q 5 M w 12 u 2 w 0 My E3a: R y 4 w W M T lda tented Aug. 9, 1927.

PATENT OFFICE.

FRANCIS M. HESS, OF WHITING, INDIANA METHOD OF AND APPARATUS FORCRACKING 011:.

Application filed. January 24, 1923. Serial 110,614,555.

This invention relates to methods of and apparatus for cracking oils,and has reference more particularly to an improved method of andapparatus for cracking oil 5 with the aid of gases produced by -arestricted internal combustion of the residuum product of distillation.It is lmown'that extraneous gas added'to the vapors in a cracking unitis an aid to cracking if said gas is rich in hydrogen and hydrogencompounds. My present invention is based on this principle,'and theleading objects of the invention are, first, to provide an improvedmethod and apparatus for efiiciently burning a portion of the residuumofthe distillation process,

which con'stitutesa very suitable fuel oil, I

to generate a gas rich in hydrogen and hydro e11 compounds, which gas isadmixed with t e vapors in the cracking unit to aid the cracking of theoil; to provide a method and apparatus whereby the heat resulting fromthe combustion of the residuum, as well as the heat that is not burned,may be utilized to heat the cracking unit itself; to restrict thecombastion; of the residuum within such teinperature limits that gasesonly are pro:

duced (with possibly anegligible amount of ash); and to provide acomplete unitary apparatus for both cracking the oil and generatingthe'gas employed to aid in the cracking in a continuous operation, and

wherein both the cracking unit or still and the gas producer operateunder the same internal pressure. I

The cracking process herein disclosed is based on the cracking processdisclosed and claimed in an application filed by me June 7, 1922, SerialNo. 566,470, with the addition of a gas producer connected to thecracking unit and operating to generate a gas rich in hydrogen andhydrogen compounds for both partially heating the heat-- ing plates ofthe still and mingling with the generated vapors to aid in the crackingof the latter. i

Inthe accompanying drawing I have illustrated a complete apparatuscapable of carrying out my improved process of oil cracking with the aidof restricted internail-combustion and embodying in a practical andpreferred form the novel structural features of my present invention;and re ferring theretoof the portion of the residuum disposed side c Thewi l.

cylindrical metal tank of suflicient strength to withstand the maximuminternal pressures employed in the system, said tank being convenientlysupported by hollow feet 6 on any suitable support indicated at 7.Mounted on the lower head of the tank are a-pair of parallel uprightframe structures designated as an entirety by 8, which constitutesupports for a pair of generally W- shaped groups (left and right) ofhollow heating plates joined at their convergent ends by hollow headersand internested so as "to form between adjacent plates of the two groupsa continuous zigzag conduit for the gravity flow of the crude materialin a broad thincontinuous film or stream from top to bottom. The heatingplates of both groups arestructurally identical and are best shown indetail in the cross-sectional view, Fig. 2, wherein 9 designates a groupof tubes by side at equally spaced indesignates each of a pair ofcorrugated boiler plates tervals and 10 longitudinally which overlie andunderlie respectively the tubes 9, and 11 designates rivets uniting thetwo plates midway between adjacent tubes '9. By this construction isformed a hollow heating plate structure which provides two separategroups of conduits for heating media, namely, the interiors of the tubes9, and the passages formed between adjacent tubes 9 and the platesections spanning adjacent tubes[ The convergent ends of each connectedpair of heating plates are united so as to render theinternal conduitsof plates continuous by the following means. '12 designates a hollowheader or manifold that extends transversely of the inner convergentendsofthe heating plates and is provided with a central longitudinalpartition or bridge plate 13 extending from end to end thereof; Eachheader carries trunnions 14 that are mounted in the frame,

uprights 8. The tubes 9 are extended through the inner wall of theheader and are fitted into the partition wall 13, whereby said tubescommunicate freely with a header chamber 15 on the outer side of thepartition 13. v The outer convergent ends of adjacent header plates areplaced in communication with each other by a generally similar headorconstruction, comprising individual headers or manifolds 12 structurallyidentical with the headers or manifolds 12, and, for the most part,having their respective inner and outer chambers connected by verticaltubes 17 and 18. The headers 12 have at, their ends trunnions 14',similar to the trunnions 14 of the headers 12, which trunnions 14 arelikewise mounted and supported in "the upright frames 8.

The above described structure affords a continuous zigzag multiple tubeconduit for the-upward flow of a heating agent (gas) compartments, an

. The above described structure: also aflords, 'a contlnuous zlgzagdownflow condult for through the heating plate tubes 9, the outer headercompartments, and the pipes 18 up to certain headers designated by 12,from which headers the gas -isreleased and discharged into the vaporchamber (interior of tank 5) through discharge pipes 19., The samestructure affords a continuous zigzag multiple tube conduit for theupward flow of residuum from the tank R through a pipe 20 and branch21through the remaining superposed heating plate tubes 9, outer headerpipes 18.

other heating media (steam and air in the present instance) deliveredthrough a pipe 22 and branches23 and 24 to the inner compartments of theheaders, the same flowing through said inner compartments, the ductsformed betweenthe tubes 9, and the pipes- 17 and thence through pipes25, 26, and an elbow 27 into a pipe 28 connected to the gas I produceras hereinafter described.

To insure the downward and forward flow of the crude material, thelongitudinal edges ,of each plate which forms a part of the trackway orpath of the material are turned upwardly, as shown-at 29 in Fi. 2 to alevel slightly above the height of the headers, thus greases within thepipe. 28 and into the top of the residuum tank R. From the outerchambers of the topmost headers 12 of the two groupsof heatingplatesthere extend up' wardly residuum dischargep'ipes 33 and 34 which areconnected into a vertical discharge pipe 35 lying within a pipe 36through which the crude material is introduced to the still and thegenerated vapors. are discharged from the still. i

Directly beneaththe lower end of the pipe 36 is a funnel 37, throughwhich the incoming crude material, together with any reflux, isdelivered to and overflows a trough 38 extending crosswise of thetopmost heating plate, by which the crude material with any refluxoverflows onto the; latter.

The resia' /umn tank;

The residuum tank used in the present apparatus preferably consists of acylindrical metal tank 40 of ample strength and capacity to servethe'purposes of the system; said'tank being connected with the bottom ofthe tank 5 of the still by a pipel41; the lower head of the tank'5having acentral aperture 42 registering with the upper end of the pipe41. Mounted within "the upper portion of the residuum tank and supportedtherefrom by hangers 43 is a box 44 forming a seal or trap for the lowerend of a gas delivery pipe 45 leading from the gas producer.

upright cylindrical structure constructed of boiler plate suflicientlyheavy to withstand the maximum internal pressure under which thecracking system is operated. The-outer metal casing or-shell 46 of theproducer is lined with a refractory material 47 to protect it from thehigh heat; and within the chamber of the producer is a fire grate '48,in the center of which is fitted the lower end of a central upwardlyextending pipe-49 leading through the top of the producer, therebyforming an annular chamber which is filled with a body of coke.designated by 50; the coke being introduced through aside opening 51closed by a removable cover 52. Above the body of coke is a secondperforated plate 53, protected by heat insulating material, on which issupporteda body of checker work 54. The space in the top of the producerchamber above the checker work communicates through a T-coupling 55with'a pipe 56, which pipe communicates at its other end through aT-coupling 57 with the upper end of the pipe 45. In the pipe is a valve58, The pipe 49 is connected through an elbow coupling 59 with ahorizontal pipe section 60, which latter is connected into the pipe 28.It will be noted that the upper portion of pipe 49, elbow 59 and pipe 60lie within and extend through the T-coupling and pipe 56.

Withinan open space 54 formed in the upper portion of the checker work54 is located a hollow ring 61 suitably apertured to form. an oilspraying device; and connected to the ring 61 is a supply pipe 62 thatextends within the main residuum discharge pipe 41 and upwardly of thelatter terminating in a flared or cup-shaped upper end 62" lyingdirectly beneath the discharge opening 42 in the bottom of the tank 5.In the pipe 62 is a valve 63. Connected into one end of the pipe 56 isa; pipe 64 equipped with a valve 65 and leading to a flue or chimney,(not shown). Connected into the lower-:endof the pipe 22 are pipes 66and 67 equipped with valves 68 and 69, respectively. In the bottom ofthe gas producer, centrally below the grate 48 is a deflector' plate 70;and from the bottom of the gas producer'a pipe 71 equipped with a valve72 leads into the residuum tank 40 at a point slightly above the bottomoi the latter.

Connected into one side of the gas producer at a point below the grate48 is a short pipe 73 equippedwith a valve 74.

valve 74 and the pipe 78 into the lower por- I may here state that theterm gas producer as used herein is not employed in the limitedtechnicalfsense'in which that term is used in the gas making art, butinthe broader and more generic sense of an apparatus for generating agas from and by the splitting up of more complex 'compounds subjectedtherein to high temperatures.

Proceeding now to a description of the method of operation, in startingthe apparatus-the valves 68, 69, 58, 72 and 63 are closed. Valves and 74are 0 ened, and

an oil burner is inserted throug the open tion of the gas producer belowthe grate 48. The said burner is supplied with air and oil from anoutside source. The oil supplied through the burner is ignited andheating is continued until the body of coke and the checker work areheated to redness, and the temperature in the upper and coolest portionof the checkerwork is raised to somewhat above 1200 F., so that a highenough temperature is maintained to insure that steam heated in thelower coke zone and dissociated to hydrogen and oxygen cannot beconverted back to steam. From this point on the heat through pipe 64 tothe outside.

ed coke acts-as a reservoir of heat for the gassifying of the residuumand the generation of hydrogen from steam and as a supply of combustiblematerial when needed.

The superposed checker work acts as a sec ondary reservoir ofheat, butat a lower temperature and also as an auxiliary distributing agent foratomized oil issuing from the spray pipe 61.

\Vhile the preliminary heating up of the gas producer goes on, theproducts of combustion escape past the open valve 65 When the desiredtemperature is reached in the top portions of the producer, the-oilburner is removed and the valve-74 is closed. Valve 68 in the .pipe 66which supplies air under pressure, and valve 69 in the pipe 67 which suplies steam are then partially opened, am d a mixture of air and steamis admitted through the line 22. This mixture of air and steam passesthrough the pipes 23 and 24, the inner chambers of the headers, and theconduits in the heating plates between the tubes 9, the pipes 25 and 26,coupling 27,

and pipes 28, 60, elbow 59, and vertical pipe 49, discharging .onto theplate by which it is deflected'upwardly through the grate 48 and intothe body of coke 50.- This mixture is maintained sufficiently rich inair to maintain the temperature existing in the .coke.

Valve 63 is now partially opened, and a small flow of oil is admitted tothe still S from the oil supply line 36 and kept flowing the flow isrestrlcted sufficiently to prevent it from overflowing the coke chamberand flowing down into the line 71, since this would tend to lower theintensit of heat in the coke chamber. In conjunction with this, themixture of air and 'steam supplied through the line 22 is held'atsuch apoint that a balanced heat condition prevails in the producer at alltimes.

With the construction described quite a latitude of temperature range ispossible in the gases discharged from the producer through the pipe 56,and the chemical structure of the-gas produced can be controlled tocreate the most desirable effect of such gas in the still on oil that isbeing cracked.

For example, a large quantity of low tembe avoided by reducing the flowof steam and air, and too low'a temperature may be avoided by increasingthe flow of steam and air. Also, if the coke volume becomes drminished,which is undesirable, this condition may be remedied by increasing thevolu'meof residuum admitted; and if, on the other hand, the coke volumeincreases, which is also undesirable, this condition may be checked bydecreasing the volume of residuum admitted. The actual amounts and ratesof flow will, of course, Vary in machines of differing sizes; but theproper volumes and rates of flow may be easily determined by experimentin any given machine by operators skilled inthe art of petroleumdistillation. Having arrived at a desirable condition in the combustioncycle, the gases escaping through the pipe 64 will be found to be richin hydrogen. When this condition is reached valve 58 is opened and valve65 is closed. The trapd l having been previously filled with some heavyfuel oil, the hot gases flowing downwardly through the pipe 45' bubblethrough the seal and upwardly into I the -pipe32, thence up through thetubes 9 arid outer-chambers of'the headers of the heating plates, beingfinally discharged into, the cracking chamber (interiorof the tankthrough the discharge pipes 19. In flowing upwardly 'through the tubularchambers of the heating plates they heat the air and steam supplytravelin downwardly through the heating plates to t e producer. The airand steam supply during its downward travel also acts as a moderator ofthe temperatureof the hot gases, and thereby effects a uniformdistribution of heat to the oil in process flowing over the heatingplates.

After the apparatus has been operated for a .short time, the tarliquefying from the hot gas lines in the cracking chamber trickles downthrough the, pipe 32 and displaces the fuel 'oil in'the seal 44. Thus,from this point on, the tar' so produced 1 serves as a seal for the gas.

The flow of feed stock from the supply.

line 36 .is now gradually increased, and the volume of gas generated inthe producer is correspondingly increased, until the necessarytemperature is developed in the still S to war-rant building thedesiredpressure. When this point is reached, a valve (not shown) in the pipe'36 (which acts both as a supply pipe and as a conduit for the vaporsand gases formed in the process) is closed, and the vapors produced inthe still and the gas generated in the producer rapidly develop thedesired pressure throughout the system. It is understood that the airand steam furnished through the lines 66 and 67 are from sources whosepressure is somewhat higher than the pressure desired in the crackingprocess.

After the desiredpressure is acquired on the cacking system, the processis carried on continuously. The oil originall supplied to the sprayingring 61 in the pro ucer is gradually replaced by the residuum of thecrack ing process, a part of this residuum being consumed in theproducer, while the remainder, overflowing the cup-shaped upper end 62of the spray supply pipe 62 flows downwardly through pipe 41 into theresiduum tank 40, from which latter it is forced by the pressure in thesystem upwardly through pipes 20 and 21 into the outer cham- [bers ofthe headers lying above the headers 12 flowing thence through theremaining heating plates in the upper portion of the cracking chamber,and being discharged through pipes 33, 34 and 35, and-thence Ipreferably following, the course of the vapors through "the balance ofthe system, butout of contact "with the vapors, as disclosed in myformer application, Serial No. 566,- 470, hereinbefore referred to.

The air and steam forced into the producer enter the heating plates atthe top" of the cracking chamber and travel through the entire seriesofheatingplates all the way to the bottom, extracting heat therefrom,and during their further travel to the bottom of the producer extractingadditional heat from the upflowing hot gases so that when they issueinto the producer they approach the temperature of the hot gases generated in the latter and to that extent relieve the work of theproducer. Any tar that is generated in the producer trickles downthrough the coke andthe bottom of the 'pro ducer chamber, and flowsthence through the pipe 71 into the residuum tank 40, the valve 72 beingopen when the apparatus is operating. The producer and residuum tankare, of'course, disposed at such relative heights that the normalworking level of the resid uum and tar in the residuum tank will bebelow the bottom of the producer.

The system is capable of continuous operation through long periodswithout requiring a shut-down for cleaning or repairs. It will be seenthat, with the exception of the extraneous heat employed in bringing theproducer initially up to the required temperature,-thefuel for heat nsedin operating the system is almost wholly supplied by and from thematerial in process of distillation;

the only exception being the relatively small amount of fuel used togenerate the heat furnished by the steam through the lines 67 and 22.The oil and residuum supplied to the producer are in just suflicientquantities to maintainthe necessary combustion within the latter withoutappreciably drawing upon the body of coke; thus requiring renewal of thelatter only at long periods .f

From the foregoing it will also be seen that the system operates as asingle unit, generating, first from the oil in process and later fromthe residuum product of the cracking operation,-a gas rich in hydrogen,

which is utilized in two-ways; first, to heat up the inflowing air andsteam and also the material in process flowing over the lower' heatingplates and, second, to mingle withthe vapors and assist the crackingprocess. This described method and means of generating such gas and itsmode of utilization constitute the chief novel features of the presentinvention. 1

I claima 1. A process ofcracking. oil, which consists i distilling theoil in the form of a thin moving film under pressure in a still,simultaneously generating from the residual products of the distillationin a separate chamber a gas rich in hydrogen, and intro-' duclng saldgas into the presence of the vapors of distillation. 1

2. A process of cracking oil which conslsts in-distilling the oil in theform of. a thin moving film under pressure in a still, simuL taneouslygenerating from the residual prod- 1 stricted internal combustionresidual products of distillation in a separate chamber under thepressure existing in the still to generate a gas rich in hydrogen, andintroducing said gas as it is generated into the presence of the vaporsof distillation in said still while said vapors are under pressure.

4:. A process of cracking oil, which consists in distilling the oil inthe form of a thin moving iilm under pressure in a still, simultaneouslyburning with the aid of restricted internal combustion residual productsof distillation in a separate chamber under the pressure existing in thestill and in the presence of steam to generate a gas vapors 0 rich inhydrogen, and introducing said gas as it is generated into the presenceof the distillation in said still while said vapors are under pressure.

5. A process of cracking oil, which consists in distilling the oil underpressure in a still, simultaneously generating from the residualproducts of the distillation by internal combustion thereof in aseparate chamber and within restricted temperature limits a hot gas richin hydrogen, transferring a part of the heat of said gas to the oil inprocess of distillation out of contactwith said oil, and thenintroducing said gas into the presence of the .vapors of distillationwhile the latter are under pressure.

6. A process of cracking oil, which consists in distilling the oil underpressure in a still, simultaneously generating from the residualproducts of distillation by internal combustion thereof in a separatechamber and within restricted temperature limits and in the presence ofhot air and steam a hot gas rich in hydrogen, transferring'a part of theheat of said gas to the oil in process of distillation and to the saidair and steam out of contact with said .oil, air and steam, and thenintroducing said gas into the presence of the vapors of distillationwhile the latter are under ressure.-

7. A process 0 cracking oil, which consistsin distilling the oilunderpressure in a still, simultaneously generating from a part of theresidual products of distillation by internal combustion thereof in aseparate chamber and within restricted temperature limits under thepressure existing in the still a hot gas rich in hydrogen, transferringa part ofthe heat of said gas to the oil in process of distillation outof contact with said oil, introducing said gas into the presence. of thevapors of distillation whilethe latter are under pressure, andtransferring heat from the remaining part of the residual products ofdistillation to the oil in proc of distillation. v

8. A process of cracking oil, which con sists in distilling the oilunder pressure in a still, simultaneously generating from a part of theresidual products of distillation by internal combustion thereof in aseparate chamber and within restricted temperature limits'under-thepressure existing in the still and in the presence of hot air and steama hot gas rich in hydrogen, transferring a part of the heat of said gasto the oil in process of distillation and to the said air and steam outof contact with said oil, air and steam,

introducing said gas into the presence of the vapors of distillationwhile the latter are producer, means for supplying oil from said stillto said producer for combustion in the latter, and means for conductingthe gas generated in said producer into said still and discharging itinto the vapors of distillation in the latter. I

10. In an apparatus for cracking oil, the combination of a pressurestill, imperforate hollow heating elements therein, a gas producer,means for supplying oil from said still to said producer for combustionin the latter, and means for conducting the gas generated in saidproducer through said eating elements and discharging it thence into thevapors of distillation in said still.

11. In an apparatus for cracking oil, the combination of a pressurestill, inclined heating plates in said still over which the oil flowsprogressively in a thin film, a gas pro ducer, a pipe for conductingresidual products of distillation from said still tosaid producer forcombustion in the latter, and means for conducting the gasgenerated in.said producer into the presence of the vapors generated in said still.

12. In, an apparatus for cracking oil,the combination of a pressurestill having imperforate hollow heating elements therein, a as producer,a pipe for conducting resid- 1miproducts of distillation from saidstillto said producer for combustion in the latter, and meansfor-conducting gas generated in said producer through heating elementsof said still and discharging it thence into the vapors of distillationin the latter.

13. In an apparatus for'cracking oil, the

combination of a pressure still, inclined heating plates in said stillover which the oil flows progressively in a thin film a gas protheducer, a residuum tank, a pipe connecting the bottom of said still withsaid residuum tank, a pipe operative to conduct a portion of theresiduum to .said producer for combustion in the latter, and meansforconducting the gas generated in said producer into presence of thevapors generated in said still.

1 1. In an apparatus for cracking oil,'the combination of a pressurestill having a residuum discharge opening in its bottom, a residuum tankbeneath said still, a residuum discharge pipe connecting said tank andstill and at its upper endsurroundingthe "discharge opening in thelatter, a gas pro ducer, a pipe for conducting residuum to said producerfor combustion in the latter, said last-named pipe .hav in an upstandingportion located within said residuum discharge pipe and formed with anopen upper end directly beneath the'discharge opening in the bottom ofsaid still, and means for conducting the gas generated in said ,producerinto the presence of the vapors generated in said still. J

15. In an apparatus for cracking oil, the combination of a pressurestill, a residuum tank beneath said still, a residuum discharge pipeconnecting the bottom of said stillwith said tank, a gas producer, meansforsupplying oil from said still tosaid producer for combustion in thelatter, apipe for conducting the gas generated in said producer intosaid still, and an oil trap interposed in said last-named pipe.

16. In an apparatus for cracking oil, the combination of a pressurestill, a residuum tank beneath said still, a residuum discharge pipeconnecting the bottom of said still with said tank, an oil trap in saidtank, a gas producer means for conducting residuum to said producer forcombustion therein, a pipe conducting gas generated in said producerinto said trap, and a pipe conducting the said gas from said trap tosaid still.

17. In an apparatus for cracking oil, the combination of a pressurestill having hollow heating elements therein, a residuumv tank, a pipeconnecting the bottom of said still with said tank, a gas producer, apipe for conducting residuum to said producer for combustion therein,means for conduct- .ing gas generated in said producer through certainheating elements of said still and discharging it thence into the vaporsof distillation in the latter, and means for conducting residuum fromsaid tank into other heating elements of said'still.

18.- In an apparatusfor cracking oil the combination of a pressurestill, inclined heating plates in said still over which the, oil howsprogressively in a thin film, a gas producer, means for supplyingresidual products of distillation from said still to said producer forcombustion in the latter, means for supplying steam to said producer,

and means for conducting the gas generated in said producer into thepresence of the vapors generated in said still.

19. In an apparatus for cracking oil the combination of a pressurestill, inclined heating plates in said still over which the oil flowsprogressively in a thin film a gas producer, means for supplyingresidual products of distillation from said still to said pro- 'ducenforcombustion in the latter, meansfor supplying steam and air underpressure to said producer; means for pre-heating said steam and air inits passage to said producer, and means for conducting the gas generatedin said producer into the presence of the vapors generated in saidstill.

i 20. In 'an apparatus .for cracking oil, the

combination of a pressure still having hollow heating elements therein,a gas producer, means for supplying oil from said still'to said producerfor combustion in the latter, means. for supplying a mixture of steamand air to one end of said hollow heating elements, a pipe .forconducting said mixture from the other end'of said heating elements tosaid producer, and a pipe for conducting the gas generated said producerinto the presence of the vapors generated in said still; said last namedpipe extending through combination of a pressure still, a gas pro-.15

said mixture conducting pipe.

21. In an apparatus for cracking oil, the combination of'a pressurestill, a gas producer, a residuum tank, a pipe connecting the bottom ofsaid still with said residuum tank, a pipe operating to conduct aportion of the residuum to said producer for combustion in the latter,means for conducting the gas generatedin said producer into the presenceof the-Vapors generated in said still,

and a return fiow pi e connecting said producer with said resi uum tank.

In an apparatus for cracking oil, the

ducer, a residuum tank, a pipe connecting the bottom of said still withsaid residuum tank, a pipe operating to conduct a portion of theresiduum from the bottom of said still to said producer for combustionin the lat- 2 ter, means for conducting the gas generated in saidproducer into t e presence of the vapors generated in said still, and areturn flow pipe connecting the bottom of said pro- 4 ducer into-saidresiduum tank.

' FRANCIS M. HESS.

